Laser induced liquid jet generating device

Abstract

A laser induced liquid jet generating device comprising: a main body 6 adapted to be filled with a specified laser beam absorbing liquid and configured such that it can contain a laser irradiating part 4 of an optical fiber from which laser beams are emitted to generate jet streams J of said liquid W by irradiating said liquid W with laser beams, with said jet streams J ejected from said main body 6 to the outside; said main body 6 comprising: a catheter mounting unit mounted integrally or in a removable manner on a catheter member 13 into which said jet stream J is introduced; a jet generating tube unit 10 in which said laser irradiation part 4 is adapted to be positioned; and a heat transfer inhibition means 11 for inhibiting thermal effect due to laser beams irradiated by said laser irradiating part 4 from being transferred outside through said jet generating tube unit 10. Thus, it provides a laser induced liquid jet generating device that is safe for both the operator and the patient as it can apply irradiation of powerful laser beams for a long period of time without the catheter being thermally affected by the laser beams.

Description

[0001] This application is based on Patent Application No. 2005-95138 filed on Mar. 29, 2005 in Japan and Patent Application No. 2006-031214 filed on Feb. 8, 2006 in Japan, the content of which is hereby incorporated by reference. BACKGROUND DISCUSSION [0002] 1. Field of the Invention [0003] The present invention relates to a laser induced liquid jet generating device that generates a jet stream by irradiating liquid with a laser beam. [0004] 2. Description of the Related Art [0005] As a way of treating thrombosis, i.e., a condition in which human blood vessels are obstructed, a treatment method of physically pulverizing matter causing thrombosis with a liquid jet stream has been discovered in recent years. This treatment method is highly appreciated as a very promising treatment method for thrombosis as it is not necessary to administer thrombolytic agents in large quantities which can cause serious adverse effects such as bleeding. Also an earlier resumption of blood flow is possi...

AI Technical Summary

Benefits of technology

[0012] A laser induced liquid jet stream generating device is relatively safe for patients and operators because the catheter is protected from the laser beam's thermal effect, thus allowing long time of irradiation with a high power laser beam.

[0014] The device does not irradiate the laser beam in a narrow catheter but irradiate the laser beam in the jet generating tube unit provided at the proximal part of the catheter and introduce the generated liquid jet stream from the tip of the jet generating tube unit into the catheter, so that it is possible to use a thinner catheter as it no longer needs to have a space inside the catheter for inserting the optical fiber, thus allowing higher powered laser beam irradiation.

[0015] Moreover, since a heat transfer inhibition means is provided outside of the jet generating tube unit for preventing the thermal effect that is caused by the laser irradiating part, the heat is not transmitted to the outside even if a high power laser irradiation is applied, so that it is safe for patients and operators. Further, it provides an improved operating maneuverability, and enables to perform extremely powerful thrombi destruction operation more securely and for long hours. Furthermore, even if a drug solution is used, cooling the vicinity of the laser irradiation part of the jet generating tube unit effectively prevents the temperature of the drug solution in the vicinity to rise excessively and maintains the activity of the drug solution without being affected.

Problems solved by technology

In particular, while it is believed that the accompanying nerve symptom becomes difficult to be improved if an ischemic condition lasts for more than six hours, an extremely high recovery effect can be expected if the resumption of blood flow occurs within a few hours of the crisis.

This may hinder the liquid jet stream from being ejected smoothly and shorten the life of the catheter itself.

There is also a concern that the heat that melts or deforms resins or metals may affect blood vessels as well.

Patients and operators who accidentally touch the laser irradiation part that has turned very hot can get burned.

A high power laser beam and the high temperature caused by it can expedite the deterioration of the material in the neighborhood of the laser irradiation part, eventually damaging the device.

Moreover, if a drug solution containing a drug such as thrombi solvent is used as the liquid to be irradiated with a laser beam to generate a jet stream, the high heat generated as a result of the laser irradiation may reduce or eliminate the efficacy of the drug in the drug solution.

Consequently, problems have arisen in minimizing how to minimize the effect of the heat generated by the laser irradiation on the outside of the catheter.

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